Humidity control apparatus

ABSTRACT

During a simple ventilation operation, in an outdoor-air conditioner ( 10 ) which is a humidity control apparatus, a first bypass damper ( 83 ) is opened to supply outdoor air to a room in unchanged form. When the outdoor temperature exceeds 35° C. during the simple ventilation operation, an operation of the outdoor-air conditioner ( 10 ) is forcibly switched to a dehumidification/ventilation operation, and then outdoor air passing through an adsorption heat exchanger ( 51, 52 ) operating as an evaporator is supplied to the room. When the outdoor temperature falls below 5° C. during the simple ventilation operation, the operation of the outdoor-air conditioner ( 10 ) is forcibly switched to a humidification/ventilation operation, and then outdoor air passing through the adsorption heat exchanger ( 51, 52 ) operating as a condenser is supplied to the room. That is, when the operation of the outdoor-air conditioner ( 10 ) is switched from the simple ventilation operation to the dehumidification/ventilation operation or the humidification/ventilation operation, a difference between the temperature of air to be supplied to the room and the room temperature is reduced as compared to that during the simple ventilation operation.

TECHNICAL FIELD

The present invention relates to a humidity control apparatus forcontrolling air humidity, and ventilating a room.

BACKGROUND ART

Conventionally, humidity control apparatuses are known, and such ahumidity control apparatus performs an operation in which outdoor air isdehumidified to be supplied to a room. Patent Document 1 discloses ahumidity control apparatus including adsorption heat exchangers withadsorbent deposited on surfaces thereof. Such a humidity controlapparatus performs a so-called “batch” action.

Specifically, the humidity control apparatus disclosed in PatentDocument 1 includes a refrigerant circuit with two adsorption heatexchangers. At predetermined time intervals, the refrigerant circuitalternately performs a first action in which the first adsorption heatexchanger serves as a condenser, and the second adsorption heatexchanger serves as an evaporator; and a second action in which thesecond adsorption heat exchanger serves as the condenser, and the firstadsorption heat exchanger serves as the evaporator. In the adsorptionheat exchanger operating as the evaporator, moisture in air adsorbs tothe adsorbent, and, at the same time, air temperature drops to someextent. In the adsorption heat exchanger operating as the condenser,moisture desorbs from the adsorbent to be imparted to air, and, at thesame time, air temperature rises to some extent.

The humidity control apparatus disclosed in Patent Document 1 supplies apart of air passing through the adsorption heat exchangers to the room,and discharges the remaining air to outside. During a dehumidificationoperation, in the humidity control apparatus, outdoor air passingthrough one of the first and second adsorption heat exchangers, whichoperates as the evaporator, is supplied to the room; and room airpassing through the other adsorption heat exchanger which operates asthe condenser is discharged to the outside.

During a humidification operation, in the humidity control apparatus,room air passing through one of the first and second adsorption heatexchangers, which operates as the evaporator, is discharged to theoutside; and outdoor air passing through the other adsorption heatexchanger which operates as the condenser is supplied to the room.

CITATION LIST Patent Document

PATENT DOCUMENT 1: Japanese Patent Publication No. 2006-078108

SUMMARY OF THE INVENTION Technical Problem

As described above, the humidity control apparatus described in PatentDocument 1 performs the operation in which the humidity of outdoor airis controlled to supply such air to the room. During transitionalperiods such as spring and autumn, a loss of comfort may not be causedin the room even if outdoor air is supplied to the room withoutcontrolling the humidity of such air. Thus, it is useless to continuethe outdoor air humidity control during such periods. However, it isnecessary to ventilate the room throughout the year, and therefore it isnecessary to continue supplying outdoor air to the room.

In order to satisfy such requirements, it may be necessary that thehumidity control apparatus performs not only a humidity controloperation (i.e., dehumidification and humidification operations) inwhich the humidity of outdoor air is controlled to supply such air tothe room, but also a simple ventilation operation in which outdoor airis supplied to the room without controlling the humidity of such air. Insuch a case, it is conceivable that, if the humidity control operationand the simple ventilation operation are switched based only on user'sswitching operations etc., the simple ventilation operation iscontinuously performed even in a case where the humidity controloperation is desired. When performing the simple ventilation operationunder significantly-high outdoor temperature or significantly-lowoutdoor temperature, a difference between the room temperature and thetemperature of outdoor air to be supplied to the room increases, therebypossibly providing discomfort to person(s) in the room.

The present invention has been made in view of the foregoing, and it isan object of the present invention to prevent the discomfort from beingprovided to the person(s) in the room during the simple ventilationoperation in the humidity control apparatus which can perform thehumidity control operation and the simple ventilation operation.

Solution to the Problem

A first aspect of the invention is intended for a humidity controlapparatus. The humidity control apparatus includes at least humiditycontrol means (50, 115, 170) for dehumidifying and cooling air, andenables a dehumidification/ventilation operation in which the humiditycontrol means (50, 115, 170) dehumidifies and cools outdoor air to besupplied to a room, and a simple ventilation operation in which thehumidity control means (50, 115, 170) is stopped to supply taken outdoorair to the room in unchanged form. The humidity control apparatusfurther includes an outdoor temperature detecting means (99) fordetecting an outdoor temperature; and a control means (64) for forciblyswitching from the simple ventilation operation to thedehumidification/ventilation operation when the outdoor temperaturedetected by the outdoor temperature detecting means (99) during thesimple ventilation operation exceeds a predetermined maximum value.

In the first aspect of the invention, the dehumidification/ventilationoperation and the simple ventilation operation are performed in ahumidity control apparatus (10). A room is generally air-conditionedwhen an outdoor temperature is high. Outdoor air having a hightemperature is supplied to the air-conditioned room in unchanged form,thereby possibly providing discomfort to person(s) in the room. Thus,when the outdoor temperature exceeds the predetermined maximum valueduring the simple ventilation operation, the control means (64) forciblyswitches an operation of the humidity control apparatus (10) from thesimple ventilation operation to the dehumidification/ventilationoperation. During the dehumidification/ventilation operation, thehumidity control means (50, 115, 170) dehumidifies and cools outdoorair. Consequently, when the operation of the humidity control apparatus(10) is switched from the simple ventilation operation to thedehumidification/ventilation operation, air having the temperature lowerthan the air temperature during the simple ventilation operation issupplied to the room.

A second aspect of the invention is intended for the humidity controlapparatus of the first aspect of the invention, in which the controlmeans (64) stops an outdoor-air supply to the room when the outdoortemperature detected by the outdoor temperature detecting means (99)exceeds the predetermined maximum value in the simple ventilationoperation performed under circumstances in which thedehumidification/ventilation operation is prohibited.

In the humidity control apparatus (10), the dehumidification/ventilationoperation may be prohibited. For example, when the humidity controlmeans (50, 115, 170) is not properly operated due to malfunctions etc.,the dehumidification/ventilation operation is prohibited. On the otherhand, the simple ventilation operation may be carried out even when thehumidity control means (50, 115, 170) is not properly operated. In sucha case, the simple ventilation operation is performed in the humiditycontrol apparatus (10) under circumstances in which thedehumidification/ventilation operation is prohibited.

Even during the simple ventilation operation performed undercircumstances in which the dehumidification/ventilation operation isprohibited, a difference between the room temperature and thetemperature of outdoor air to be supplied to the room is significantlyincreased, thereby causing a loss of comfort of person(s) in the room.However, since the dehumidification/ventilation operation is prohibitedin such a case, a decline in the comfort cannot be prevented byswitching the operation of the humidity control apparatus (10) from thesimple ventilation operation to the dehumidification/ventilationoperation. In such a case, the control means (64) of the second aspectof the invention stops the outdoor-air supply to the room in order toprevent the decline in the comfort.

A third aspect of the invention is intended for the humidity controlapparatus of the first or second aspect of the invention, in which thehumidity control means (50, 115) includes adsorption units (51, 52, 111,112) with adsorbent to be exposed to air, and dehumidifies air byadsorbing moisture in the air onto the adsorption unit (51, 52, 111,112).

In the third aspect of the invention, the adsorption units (51, 52, 111,112) are provided in the humidity control means (50, 115). During thedehumidification/ventilation operation, the humidity control means (50,115) allows the adsorbent of the adsorption unit (51, 52, 111, 112) tobe exposed to outdoor air, thereby adsorbing moisture in the outdoor aironto the adsorption unit (51, 52, 111, 112).

A fourth aspect of the invention is intended for a humidity controlapparatus. The humidity control apparatus includes at least humiditycontrol means (50, 115, 170) for humidifying and heating air, andenables a humidification/ventilation operation in which the humiditycontrol means (50, 115, 170) humidifies and heats outdoor air to besupplied to a room, and a simple ventilation operation in which thehumidity control means (50, 115, 170) is stopped to supply taken outdoorair to the room in unchanged form. The humidity control apparatusfurther includes outdoor temperature detecting means (99) for detectingan outdoor temperature; and control means (64) for forcibly switchingfrom the simple ventilation operation to the humidification/ventilationoperation when the outdoor temperature detected by the outdoortemperature detecting means (99) during the simple ventilation operationfalls below a predetermined minimum value.

In the fourth aspect of the invention, the humidification/ventilationoperation and the simple ventilation operation are performed in ahumidity control apparatus (10). A room is generally heated when anoutdoor temperature is low. Outdoor air having a low temperature issupplied to the heated room in unchanged form, thereby possiblyproviding discomfort to person(s) in the room. Thus, when the outdoortemperature falls below the predetermined minimum value during thesimple ventilation operation, the ventilation control section (64)forcibly switches the operation of the humidity control apparatus (10)from the simple ventilation operation to the humidification/ventilationoperation. During the humidification/ventilation operation, the humiditycontrol means (50, 115, 170) humidifies and heats outdoor air.Consequently, when the operation of the humidity control apparatus (10)is switched from the simple ventilation operation to thehumidification/ventilation operation, air having the temperature higherthan the air temperature during the simple ventilation operation issupplied to the room.

A fifth aspect of the invention is intended for the humidity controlapparatus of the fourth aspect of the invention, in which the controlmeans (64) stops an outdoor-air supply to the room when the outdoortemperature detected by the outdoor temperature detecting means (99)falls below the predetermined minimum value in the simple ventilationoperation performed under circumstances in which thehumidification/ventilation operation is prohibited.

In the humidity control apparatus (10), the humidification/ventilationoperation may be prohibited. For example, when the humidity controlmeans (50, 115, 170) is not properly operated due to malfunctions etc.,the humidification/ventilation operation is prohibited. On the otherhand, the simple ventilation operation may be carried out even when thehumidity control means (50, 115, 170) is not properly operated. In sucha case, the simple ventilation operation is performed in the humiditycontrol apparatus (10) under circumstances in which thehumidification/ventilation operation is prohibited.

Even during the simple ventilation operation performed undercircumstances in which the humidification/ventilation operation isprohibited, the difference between the room temperature and thetemperature of outdoor air to be supplied to the room is significantlyincreased, thereby causing the loss of comfort of person(s) in the room.However, since the humidification/ventilation operation is prohibited insuch a case, the decline in the comfort cannot be prevented by switchingthe operation of the humidity control apparatus (10) from the simpleventilation operation to the humidification/ventilation operation. Insuch a case, the control means (64) of the fifth aspect of the inventionstops the outdoor-air supply to the room in order to prevent the declinein the comfort.

A sixth aspect of the invention is intended for the humidity controlapparatus of the fourth or fifth aspect of the invention, in which thehumidity control means (50, 115) includes adsorption units (51, 52, 111,112) with adsorbent to be exposed to air, and humidifies air byimparting moisture desorbed from the adsorbent of the adsorption unit(51, 52, 111, 112), to the air.

In the sixth aspect of the invention, the adsorption units (51, 52, 111,112) are provided in the humidity control means (50, 115). During thehumidification/ventilation operation, the humidity control means (50,115) allows the adsorbent of the adsorption unit (51, 52, 111, 112) tobe exposed to outdoor air, thereby imparting moisture desorbed from theadsorbent, to the outdoor air.

A seventh aspect of the invention is intended for the humidity controlapparatus of the third aspect of the invention, in which the humiditycontrol means includes adsorption heat exchangers (51, 52) withadsorbent deposited on surfaces thereof as the adsorption units, andincludes a refrigerant circuit (50) in which the adsorption heatexchangers (51, 52) are connected to each other to perform arefrigeration cycle; and the refrigerant circuit (50) performs anadsorption action in which the adsorbent of the adsorption heatexchanger (51, 52) is cooled by refrigerant to adsorb moisture in aironto the adsorption heat exchanger (51, 52), and a recovery action inwhich the adsorbent of the adsorption heat exchanger (51, 52) is heatedby refrigerant for recovery of the adsorbent in the adsorption heatexchanger (51, 52).

A eighth aspect of the invention is intended for the humidity controlapparatus of the sixth aspect of the invention, in which the humiditycontrol means adsorption heat exchangers (51, 52) with adsorbentdeposited on surfaces thereof as the adsorption units, and includes arefrigerant circuit (50) in which the adsorption heat exchangers (51,52) are connected to each other to perform a refrigeration cycle; andthe refrigerant circuit (50) performs an adsorption action in which theadsorbent of the adsorption heat exchanger (51, 52) is cooled byrefrigerant to adsorb moisture in air onto the adsorption heat exchanger(51, 52), and a recovery action in which the adsorbent of the adsorptionheat exchanger (51, 52) is heated by refrigerant for recovery of theadsorbent in the adsorption heat exchanger (51, 52).

In the seventh and eighth aspects of the invention, the refrigerantcircuit (50) is provided in the humidity control means. The adsorptionheat exchangers (51, 52) serving as the adsorption units are connectedto the refrigerant circuit (50). The refrigerant circuit (50) performsthe adsorption action and the recovery action. During the adsorptionaction, in the adsorption heat exchanger (51, 52), moisture in airadsorbs to the adsorbent, and adsorption heat generated thereupon isremoved by refrigerant. At this point, the air passing through theadsorption heat exchanger (51, 52) during the adsorption action iscooled by refrigerant, thereby decreasing the temperature thereof tosome extent. During the recovery action, in the adsorption heatexchanger (51, 52), moisture desorbs from the adsorbent heated byrefrigerant. At this point, the air passing through the adsorption heatexchanger (51, 52) during the recovery action is heated by refrigerant,thereby increasing the temperature thereof to some extent. In therefrigerant circuit (50) of these aspects of the invention, a singleadsorption heat exchanger may be connected to selectively perform theadsorption action and the recovery action, or two adsorption heatexchangers may be connected to each other so that the adsorption actionin one of the adsorption heat exchangers, and the recovery action in theother adsorption heat exchanger are performed simultaneously, i.e., inparallel.

ADVANTAGES OF THE INVENTION

In the first aspect of the invention, when the outdoor temperatureexceeds the predetermined maximum value during the simple ventilationoperation, the control means (64) forcibly switches the operation of thehumidity control apparatus (10) from the simple ventilation operation tothe dehumidification/ventilation operation, thereby decreasing thetemperature of air sent into the room. In addition, in the fourth aspectof the invention, when the outdoor temperature falls below thepredetermined minimum value during the simple ventilation operation, thecontrol means (64) forcibly switches the operation of the humiditycontrol apparatus (10) from the simple ventilation operation to thehumidification/ventilation operation, thereby increasing the temperatureof air sent into the room. Thus, according to the present invention, thedifference between the temperature of air supplied from the humiditycontrol apparatus (10) to the room and the room temperature can beprevented from increasing, thereby ensuring the comfort in the room.

In the second aspect of the invention, when the outdoor temperatureexceeds the predetermined maximum value during the simple ventilationoperation performed under circumstances in which thedehumidification/ventilation operation is prohibited, the control means(64) stops the outdoor-air supply to the room. In addition, in the fifthaspect of the invention, when outdoor temperature falls below thepredetermined minimum value during the simple ventilation operationperformed under circumstances in which the humidification/ventilationoperation is prohibited, the control means (64) stops the outdoor-airsupply to the room. Thus, according to these aspects of the invention,even if the dehumidification/ventilation operation or thehumidification/ventilation operation cannot be carried out, the declinein the comfort in the room can be reliably prevented.

In the seventh and eighth aspects of the invention, the refrigerantcircuit (50) provided in the humidity control means performs theadsorption action and the recovery action. The dehumidification andcooling of air are performed in parallel in the adsorption heatexchanger (51, 52) during the adsorption action, and the humidificationand heating of air are performed in parallel in the adsorption heatexchanger (51, 52) during the recovery action. That is, in the humiditycontrol means, the air humidity and temperature controls are performedat a single section. Thus, according to these aspects of the invention,the structure of the outdoor-air conditioner (10) can be simplified ascompared to a case where the air humidity and temperature controls areperformed by using separate members.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outdoor-air conditioner as viewedfrom a front side, which is illustrated without a part of a casing andan electrical component box.

FIG. 2 are plan, right side, and left side views which are schematicallyillustrated without a part of the outdoor-air conditioner.

FIG. 3 are plumbing diagrams illustrating a structure of a refrigerantcircuit. FIG. 3(A) illustrates a first action. FIG. 3(B) illustrates asecond action.

FIG. 4 are schematic plan, right side, and left side views of theoutdoor-air conditioner, which illustrate an air flow in a first actionof a dehumidification/ventilation operation.

FIG. 5 are schematic plan, right side, and left side views of theoutdoor-air conditioner, which illustrate an air flow in a second actionof the dehumidification/ventilation operation.

FIG. 6 are schematic plan, right side, and left side views of theoutdoor-air conditioner, which illustrate an air flow in a first actionof a humidification/ventilation operation.

FIG. 7 are schematic plan, right side, and left side views of theoutdoor-air conditioner, which illustrate an air flow in a second actionof the humidification/ventilation operation.

FIG. 8 are schematic plan, right side, and left side views of theoutdoor-air conditioner, which illustrate an air flow in a simpleventilation operation.

FIG. 9 is a block diagram of a structure of a controller (60) of theoutdoor-air conditioner.

FIG. 10 is a state transition diagram of an action performed by aventilation control section (64) of the controller (60).

FIG. 11 is a state transition diagram of an action performed by theventilation control section (64) of the controller (60).

FIG. 12 are schematic diagrams of a structure of an outdoor-airconditioner of a third variation of an embodiment. FIG. 12(A)illustrates a first action. FIG. 12(B) illustrates a second action.

FIG. 13 is a schematic diagram of a structure of an outdoor-airconditioner of a fourth variation of the embodiment.

DESCRIPTION OF REFERENCE CHARACTERS

-   10 Outdoor-Air Conditioner (Humidity Control Apparatus)-   50 Refrigerant Circuit (Humidity Control Means)-   51 First Adsorption Heat Exchanger (Adsorption Unit)-   52 Second Adsorption Heat Exchanger (Adsorption Unit)-   64 Ventilation Control Section (Control Means)-   99 External-Air Temperature Sensor (Outdoor-Air Temperature    Detecting Means)-   111 First Adsorption Element (Adsorption Unit)-   112 Second Adsorption Element (Adsorption Unit)-   115 Humidity Control Means-   170 Humidity Control Means

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described in detailhereinafter with reference to the drawings. An outdoor-air conditioner(10) of the present embodiment is for controlling humidity in a room,and ventilating the room, and serves as a humidity control apparatus.The outdoor-air conditioner (10) controls the humidity of taken outdoorair (OA) to supply such air to the room, and, at the same time,discharges taken room air (RA) to outside.

<Entire Structure of Outdoor-Air Conditioner>

The outdoor-air conditioner (10) will be described with reference toFIGS. 1 and 2 as necessary. Unless otherwise specified, terms “upper,”“lower,” “left,” “right,” “front,” “rear,” “near,” and “back” usedherein designate directions when the outdoor-air conditioner (10) isviewed from a frontal side.

The outdoor-air conditioner (10) includes a casing (11). A refrigerantcircuit (50) is accommodated in the casing (11). In the refrigerantcircuit (50), a first adsorption heat exchanger (51), a secondadsorption heat exchanger (52), a compressor (53), a four-way switchingvalve (54), and an electric-operated expansion valve (55) are connectedto each other. The refrigerant circuit (50) will be described in detaillater.

The casing (11) is formed in an approximately-flatrectangular-parallelepiped shape with a relatively-low height. In thecasing (11) illustrated in FIG. 1, a side surface on a near-left side(i.e., frontal surface) serves as a frontal panel section (12); a sidesurface on a back-right side (i.e., dorsal surface) serves as a dorsalpanel section (13); a side surface on a near-right side serves as afirst side panel section (14); and a side surface on a back-left sideserves as a second side panel section (15).

The casing (11) includes an outdoor air suction port (24); a room airsuction port (23); an air supply port (22); and an air discharge port(21). The outdoor air suction port (24) and the room air suction port(23) open in the dorsal panel section (13). The outdoor air suction port(24) is arranged in a lower portion of the dorsal panel section (13).The room air suction port (23) is arranged in an upper portion of thedorsal panel section (13). The air supply port (22) is arranged close toan end portion of the first side panel section (14) on the frontal panelsection (12) side. The air discharge port (21) is arranged close to anend portion of the second side panel section (15) on the frontal panelsection (12) side.

An inner space of the casing (11) includes an upstream partition plate(71); a downstream partition plate (72); a central partition plate (73);a first partition plate (74); and a second partition plate (75). Thepartition plates (71-75) are vertically arranged on a bottom plate ofthe casing (11), and extend from the bottom plate to an top plate of thecasing (11) to divide the inner space of the casing (11).

The upstream partition plate (71) and the downstream partition plate(72) are arranged in a front-rear direction of the casing (11) atpredetermined intervals so as to be parallel to the frontal panelsection (12) and the dorsal panel section (13). The upstream partitionplate (71) is arranged closer to the dorsal panel section (13). Thedownstream partition plate (72) is arranged closer to the frontal panelsection (12).

The first partition plate (74) and the second partition plate (75) arearranged so as to be parallel to the first side panel section (14) andthe second side panel section (15). The first partition plate (74) isarranged at a predetermined interval from the first side panel section(14) so as to close a space between the upstream partition plate (71)and the downstream partition plate (72) from the right side. The secondpartition plate (75) is arranged at a predetermined interval from thesecond side panel section (15) so as to close the space between theupstream partition plate (71) and the downstream partition plate (72)from the left side.

The central partition plate (73) is arranged between the upstreampartition plate (71) and the downstream partition plate (72) so as to beperpendicular to the upstream partition plate (71) and the downstreampartition plate (72). The central partition plate (73) is provided so asto extend from the upstream partition plate (71) to the downstreampartition plate (72), and divides the space between the upstreampartition plate (71) and the downstream partition plate (72) into rightand left spaces.

In the casing (11), a space between the upstream partition plate (71)and the dorsal panel section (13) is divided into two upper and lowerspaces. The upper space serves as a room air path (32), and the lowerspace serves as an outdoor air path (34). The room air path (32)communicates with the room through a duct connected to the room airsuction port (23). In the room air path (32), a room air filter (27), aroom air humidity sensor (96), and a room air temperature sensor (98)are installed. The outdoor air path (34) communicates with an outdoorspace through a duct connected to the outdoor air suction port (24). Inthe outdoor air path (34), an outdoor air filter (28), an outdoor airhumidity sensor (97), and an outdoor air temperature sensor (99) areinstalled.

The room air humidity sensor (96) measures the relative humidity of roomair flowing into the room air path (32). The room air temperature sensor(98) measures the temperature of room air flowing into the room air path(32). The room air temperature sensor (98) serves as a room temperaturedetecting means for detecting a room temperature. The outdoor airhumidity sensor (97) measures the relative humidity of outdoor airflowing into the outdoor air path (34). The outdoor air temperaturesensor (99) measures the temperature of outdoor air flowing into theoutdoor air path (34). The outdoor air temperature sensor (99) serves asan outdoor temperature detecting means for detecting an outdoortemperature.

The space between the upstream partition plate (71) and the downstreampartition plate (72) in the casing (11) is divided into the right andleft spaces by the central partition plate (73). The right space withrespect to the central partition plate (73) serves as a first heatexchange chamber (37), and the left space with respect to the centralpartition plate (73) serves as a second heat exchange chamber (38). Thefirst adsorption heat exchanger (51) is accommodated in the first heatexchange chamber (37). The second adsorption heat exchanger (52) isaccommodated in the second heat exchange chamber (38). Although notillustrated in the figure, the electric-operated expansion valve (55) ofthe refrigerant circuit (50) is accommodated in the first heat exchangechamber (37).

Each of the adsorption heat exchangers (51, 52) is a so-called“cross-fin-type fin-and-tube heat exchanger” with adsorbent deposited ona surface thereof, and is formed in a thick rectangular plate-like shapeor a flat rectangular-parallelepiped shape as a whole. The adsorptionheat exchangers (51, 52) serve as adsorption units for exposing theadsorbent to air. The adsorption heat exchangers (51, 52) are verticallyarranged in the heat exchange chambers (37, 38) so that frontal anddorsal surfaces thereof are parallel to the upstream partition plate(71) and the downstream partition plate (72).

In the inner space of the casing (11), a space along a frontal surfaceof the downstream partition plate (72) is divided into upper and lowerspaces. The upper portion of the horizontally-divided spaces serves asan air supply path (31), and the lower portion serves as an airdischarge path (33).

Four openable dampers (41-44) are provided in the upstream partitionplate (71). Each of the dampers (41-44) is formed in an approximatelyhorizontally-elongated rectangular shape. Specifically, in a portion ofthe upstream partition plate (71), which faces the room air path (32)(upper portion), a first room air damper (41) is attached on the rightside with respect to the central partition plate (73), and a second roomair damper (42) is attached on the left side with respect to the centralpartition plate (73). In a portion of the upstream partition plate (71),which faces the outdoor air path (34) (lower portion), a first outdoorair damper (43) is attached on the right side with respect to thecentral partition plate (73), and a second outdoor air damper (44) isattached on the left side with respect to the central partition plate(73).

Four openable dampers (45-48) are provided in the downstream partitionplate (72). Each of the dampers (45-48) is formed in an approximatelyhorizontally-elongated rectangular shape. Specifically, in a portion ofthe downstream partition plate (72), which faces the air supply path(31) (upper portion), a first air supply damper (45) is attached on theright side with respect to the central partition plate (73), and asecond air supply damper (46) is attached on the left side with respectto the central partition plate (73). In a portion of the downstreampartition plate (72), which faces the air discharge path (33) (lowerportion), a first air discharge damper (47) is attached on the rightside with respect to the central partition plate (73), and a second airdischarge damper (48) is attached on the left side with respect to thecentral partition plate (73).

In the casing (11), a space between the air supply path (31) and the airdischarge path (33), and the frontal panel section (12) is divided intoright and left spaces by a partition plate (77). The right space withrespect to the partition plate (77) serves as an air supply fan chamber(36), and the left space with respect to the partition plate (77) servesas an air discharge fan chamber (35).

An air supply fan (26) is accommodated in the air supply fan chamber(36). An air discharge fan (25) is accommodated in the air discharge fanchamber (35). The air supply fan (26) and the air discharge fan (25) arecentrifugal multi-blade fans (so-called “sirocco” fans). The air supplyfan (26) blows air sucked from the downstream partition plate (72) side,through the air supply port (22). The air discharge fan (25) blows airsucked from the downstream partition plate (72) side, through the airdischarge port (21).

The compressor (53) and the four-way switching valve (54) of therefrigerant circuit (50) are accommodated in the air supply fan chamber(36). The compressor (53) and the four-way switching valve (54) arearranged between the air supply fan (26) and the partition plate (77) inthe air supply fan chamber (36).

In the casing (11), a space between the first partition plate (74) andthe first side panel section (14) serves as a first bypass path (81). Astart point of the first bypass path (81) communicates only with theoutdoor air path (34), and is isolated from the room air path (32). Aterminal point of the first bypass path (81) is separated from the airsupply path (31), the air discharge path (33), and the air supply fanchamber (36) by a partition plate (78). A portion of the partition plate(78), which faces the air supply fan chamber (36), is provided with afirst bypass damper (83).

In the casing (11), a space between the second partition plate (75) andthe second side panel section (15) serves as a second bypass path (82).A start point of the second bypass path (82) communicates only with theroom air path (32), and is isolated from the outdoor air path (34). Aterminal point of the second bypass path (82) is separated from the airsupply path (31), the air discharge path (33), and the air discharge fanchamber (35) by a partition plate (79). A portion of the partition plate(79), which faces the air discharge fan chamber (35), is provided with asecond bypass damper (84).

The right and left side views of FIG. 2 are illustrated without thefirst bypass path (81), the second bypass path (82), the first bypassdamper (83), and the second bypass damper (84).

<Structure of Refrigerant Circuit>

As illustrated in FIG. 3, the refrigerant circuit (50) is a closedcircuit including the first adsorption heat exchanger (51); the secondadsorption heat exchanger (52); the compressor (53); the four-wayswitching valve (54); and the electric-operated expansion valve (55). Inthe refrigerant circuit (50), filled refrigerant circulates to perform avapor compression refrigeration cycle. The refrigerant circuit (50)serves as a humidity control means.

In the refrigerant circuit (50), a discharge side of the compressor (53)is connected to a first port of the four-way switching valve (54), and asuction side thereof is connected to a second port of the four-wayswitching valve (54). In addition, in the refrigerant circuit (50), thefirst adsorption heat exchanger (51), the electric-operated expansionvalve (55), and the second adsorption heat exchanger (52) aresequentially connected to each other from a third port toward a fourthport of the four-way switching valve (54).

The four-way switching valve (54) can be switched between a first state(state illustrated in FIG. 3(A)) in which the first port communicateswith the third port with the second port communicating with the fourthport, and a second state (state illustrated in FIG. 3(B)) in which thefirst port communicates with the fourth port with the second portcommunicating with the third port.

In the refrigerant circuit (50), a high-pressure sensor (91) and adischarge pipe temperature sensor (93) are attached to a pipe connectingbetween the discharge side of the compressor (53) and the first port ofthe four-way switching valve (54). The high-pressure sensor (91)measures the pressure of refrigerant discharged from the compressor(53). The discharge pipe temperature sensor (93) measures thetemperature of refrigerant discharged from the compressor (53).

In addition, in the refrigerant circuit (50), a low-pressure sensor (92)and a suction pipe temperature sensor (94) are attached to a pipeconnecting between the suction side of the compressor (53) and thesecond port of the four-way switching valve (54). The low-pressuresensor (92) measures the pressure of refrigerant sucked into thecompressor (53). The suction pipe temperature sensor (94) measures thetemperature of refrigerant sucked into the compressor (53).

Further, in the refrigerant circuit (50), a pipe temperature sensor (95)is attached to a pipe connecting between the third port of the four-wayswitching valve (54) and the first adsorption heat exchanger (51). Thepipe temperature sensor (95) is arranged close to the four-way switchingvalve (54) in such a pipe, and measures the temperature of refrigerantflowing through the pipe.

<Structure of Controller>

A controller (60) is provided in the outdoor-air conditioner (10).Although not illustrated in FIGS. 1 and 2, an electrical component boxis attached to the frontal panel section (12) of the casing (11), and acontrol board accommodated in the electrical component box serves as thecontroller (60).

As illustrated in FIG. 9, the controller (60) includes an outdoor airabsolute humidity calculating section (61); an outdoor air dew-pointtemperature calculating section (62); an operation command input section(63); and a ventilation control section (64). Measured values of theroom air humidity sensor (96), the room air temperature sensor (98), theoutdoor air humidity sensor (97), and the outdoor air temperature sensor(99) are inputted to the controller (60). Further, measured values ofthe sensors (91, 92, . . . ) provided in the refrigerant circuit (50)are inputted to the controller (60). The controller (60) controls anoperation of the outdoor-air conditioner (10) based on such inputtedmeasured values.

The outdoor air absolute humidity calculating section (61) calculatesthe absolute humidity of outdoor air by using the outdoor air relativehumidity measured by the outdoor air humidity sensor (97), and using theoutdoor air temperature measured by the outdoor air temperature sensor(99). The outdoor air dew-point temperature calculating section (62)calculates the dew-point temperature of outdoor air by using the outdoorair absolute humidity calculated by the outdoor air absolute humiditycalculating section (61). As described above, in the outdoor-airconditioner (10) of the present embodiment, an outdoor dew-pointtemperature detecting means (65) is constituted by the outdoor airhumidity sensor (97), the outdoor air temperature sensor (99), theoutdoor air absolute humidity calculating section (61), and the outdoorair dew-point temperature calculating section (62).

A command signal is inputted to the operation command input section (63)by a user with a remote controller etc. In the outdoor-air conditioner(10) of the present embodiment, four operation modes (dehumidificationmode, humidification mode, humidity control mode, and ventilation mode)can be selected. Basically, only a dehumidification/ventilationoperation which will be described later is performed in thedehumidification mode; only a humidification/ventilation operation whichwill be described later is performed in the humidification mode; andonly a simple ventilation operation which will be described later isperformed in the ventilation mode. In addition, basically, one of thedehumidification/ventilation operation and thehumidification/ventilation operation is automatically selected in thehumidity control mode. When a user selects any of the four operationmodes by an operation of a remote controller etc., a command signalcorresponding to the selected operation mode is inputted to theoperation command input section (63). The controller (60) controlsactions of the dampers (41-48) etc. so that the operation modecorresponding to the command signal inputted to the operation commandinput section (63) is executed in the outdoor-air conditioner (10).

When predetermined conditions are satisfied, the ventilation controlsection (64) forcibly switches the operation of the outdoor-airconditioner (10) to either one of the dehumidification/ventilationoperation and the humidification/ventilation operation. When thepredetermined conditions are satisfied during the simple ventilationoperation, the ventilation control section (64) forcibly stops the airsupply fan (26). As described above, the ventilation control section(64) serves as a control means. A control operation of the ventilationcontrol section (64) will be described in detail later.

Operation

The outdoor-air conditioner (10) of the present embodiment selectivelyperforms the dehumidification/ventilation operation, thehumidification/ventilation operation, and the simple ventilationoperation. During the dehumidification/ventilation operation or thehumidification/ventilation operation, the outdoor-air conditioner (10)controls the humidity of taken outdoor air (OA) to supply such air tothe room as supply air (SA), and, at the same time, discharges takenroom air (RA) to the outside as exhaust air (EA). On the other hand,during the simple ventilation operation, the outdoor-air conditioner(10) supplies taken outdoor air (OA) to the room as supply air (SA) inunchanged form, and, at the same time, discharges taken room air (RA) tothe outside as exhaust air (EA) in unchanged form.

<Dehumidification/Ventilation Operation>

In the dehumidification/ventilation operation, the outdoor-airconditioner (10) alternately repeats first and second actions which willbe described later, at predetermined time intervals (e.g., three-minuteintervals). During the dehumidification/ventilation operation, the firstbypass damper (83) and the second bypass damper (84) are kept closed.

In the dehumidification/ventilation operation, the outdoor-airconditioner (10) takes outdoor air into the casing (11) through theoutdoor air suction port (24) as first air, and takes room air into thecasing (11) through the room air suction port (23) as second air.

First, the first action of the dehumidification/ventilation operationwill be described. As illustrated in FIG. 4, during the first action,the first room air damper (41), the second outdoor air damper (44), thesecond air supply damper (46), and the first air discharge damper (47)are opened; and the second room air damper (42), the first outdoor airdamper (43), the first air supply damper (45), and the second airdischarge damper (48) are closed. During the first action, the four-wayswitching valve (54) is set to the first state (state illustrated inFIG. 3(A)) in the refrigerant circuit (50). The first adsorption heatexchanger (51) serves as a condenser, and the second adsorption heatexchanger (52) serves as an evaporator. That is, in the refrigerantcircuit (50), a recovery action in the first adsorption heat exchanger(51) and an adsorption action in the second adsorption heat exchanger(52) are performed simultaneously, i.e., in parallel.

The first air flows into the outdoor air path (34) to pass through theoutdoor air filter (28), and then flows into the second heat exchangechamber (38) through the second outdoor air damper (44). Subsequently,the first air passes through the second adsorption heat exchanger (52).In the second adsorption heat exchanger (52), moisture in the first airadsorbs to the adsorbent, and then adsorption heat generated thereuponis absorbed by refrigerant. The first air dehumidified in the secondadsorption heat exchanger (52) flows into the air supply path (31)through the second air supply damper (46). After the first air passesthrough the air supply fan chamber (36), the first air is supplied tothe room through the air supply port (22).

On the other hand, the second air flows into the room air path (32) topass through the room air filter (27), and then flows into the firstheat exchange chamber (37) through the first room air damper (41).Subsequently, the second air passes through the first adsorption heatexchanger (51). In the first adsorption heat exchanger (51), moisturedesorbs from the adsorbent heated by refrigerant, and then the desorbedmoisture is imparted to the second air. The second air to which moistureis imparted in the first adsorption heat exchanger (51) flows into theair discharge path (33) through the first air discharge damper (47).After the second air passes through the air discharge fan chamber (35),the second air is discharged to the outside through the air dischargeport (21).

Next, the second action of the dehumidification/ventilation operationwill be described. As illustrated in FIG. 5, during the second action,the second room air damper (42), the first outdoor air damper (43), thefirst air supply damper (45), and the second air discharge damper (48)are opened; and the first room air damper (41), the second outdoor airdamper (44), the second air supply damper (46), and the first airdischarge damper (47) are closed. During the second action, the four-wayswitching valve (54) is set to the second state (state illustrated inFIG. 3(B)) in the refrigerant circuit (50). The first adsorption heatexchanger (51) serves as the evaporator, and the second adsorption heatexchanger (52) serves as the condenser. That is, in the refrigerantcircuit (50), the adsorption action in the first adsorption heatexchanger (51) and the recovery action in the second adsorption heatexchanger (52) are performed simultaneously, i.e., in parallel.

The first air flows into the outdoor air path (34) to pass through theoutdoor air filter (28), and then flows into the first heat exchangechamber (37) through the first outdoor air damper (43). Subsequently,the first air passes through the first adsorption heat exchanger (51).In the first adsorption heat exchanger (51), moisture in the first airadsorbs to the adsorbent, and then adsorption heat generated thereuponis absorbed by refrigerant. The first air dehumidified in the firstadsorption heat exchanger (51) flows into the air supply path (31)through the first air supply damper (45). After the first air passesthrough the air supply fan chamber (36), the first air is supplied tothe room through the air supply port (22).

On the other hand, the second air flows into the room air path (32) topass through the room air filter (27), and then flows into the secondheat exchange chamber (38) through the second room air damper (42).Subsequently, the second air passes through the second adsorption heatexchanger (52). In the second adsorption heat exchanger (52), moisturedesorbs from the adsorbent heated by refrigerant, and then the desorbedmoisture is imparted to the second air. The second air to which moistureis imparted in the second adsorption heat exchanger (52) flows into theair discharge path (33) through the second air discharge damper (48).After the second air passes through the air discharge fan chamber (35),the second air is discharged to the outside through the air dischargeport (21).

<Humidification/Ventilation Operation>

In the humidification/ventilation operation, the outdoor-air conditioner(10) alternately repeats first and second actions which will bedescribed later, at predetermined time intervals (e.g., four-minuteintervals). During the humidification/ventilation operation, the firstbypass damper (83) and the second bypass damper (84) are kept closed.

In the humidification/ventilation operation, the outdoor-air conditioner(10) takes outdoor air into the casing (11) through the outdoor airsuction port (24) as second air, and takes room air into the casing (11)through the room air suction port (23) as first air.

First, the first action of the humidification/ventilation operation willbe described. As illustrated in FIG. 6, during the first action, thesecond room air damper (42), the first outdoor air damper (43), thefirst air supply damper (45), and the second air discharge damper (48)are opened; and the first room air damper (41), the second outdoor airdamper (44), the second air supply damper (46), and first air dischargedamper (47) are closed. During the first action, the four-way switchingvalve (54) is set to the first state (state illustrated in FIG. 3(A)) inthe refrigerant circuit (50). The first adsorption heat exchanger (51)serves as the condenser, and the second adsorption heat exchanger (52)serves as the evaporator. That is, in the refrigerant circuit (50), therecovery action in the first adsorption heat exchanger (51) and theadsorption action in the second adsorption heat exchanger (52) areperformed simultaneously, i.e., in parallel.

The first air flows into the room air path (32) to pass through the roomair filter (27), and then flows into the second heat exchange chamber(38) through the second room air damper (42). Subsequently, the firstair passes through the second adsorption heat exchanger (52). In thesecond adsorption heat exchanger (52), moisture in the first air adsorbsto the adsorbent, and then adsorption heat generated thereupon isabsorbed by refrigerant. The first air from which moisture is removed inthe second adsorption heat exchanger (52) flows into the air dischargepath (33) through the second air discharge damper (48). After the firstair passes through the air discharge fan chamber (35), the first air isdischarged to the outside through the air discharge port (21).

On the other hand, the second air flows into the outdoor air path (34)to pass through the outdoor air filter (28), and then flows into thefirst heat exchange chamber (37) through the first outdoor air damper(43). Subsequently, the second air passes through the first adsorptionheat exchanger (51). In the first adsorption heat exchanger (51),moisture desorbs from the adsorbent heated by refrigerant, and then thedesorbed moisture is imparted to the second air. The second airhumidified in the first adsorption heat exchanger (51) flows into theair supply path (31) through the first air supply damper (45). After thesecond air passes through the air supply fan chamber (36), the secondair is supplied to the room through the air supply port (22).

Next, the second action of the humidification/ventilation operation willbe described. As illustrated in FIG. 7, during the second action, thefirst room air damper (41), the second outdoor air damper (44), thesecond air supply damper (46), and the first air discharge damper (47)are opened; and the second room air damper (42), the first outdoor airdamper (43), the first air supply damper (45), and the second airdischarge damper (48) are closed. During the second action, the four-wayswitching valve (54) is set to the second state (state illustrated inFIG. 3(B)) in the refrigerant circuit (50). The first adsorption heatexchanger (51) serves as the evaporator, and the second adsorption heatexchanger (52) serves as the condenser. That is, in the refrigerantcircuit (50), the adsorption action in the first adsorption heatexchanger (51) and the recovery action in the second adsorption heatexchanger (52) are performed simultaneously, i.e., in parallel.

The first air flows into the room air path (32) to pass through the roomair filter (27), and then flows into the first heat exchange chamber(37) through the first room air damper (41). Subsequently, the first airpasses through the first adsorption heat exchanger (51). In the firstadsorption heat exchanger (51), moisture in the first air adsorbs to theadsorbent, and then adsorption heat generated thereupon is absorbed byrefrigerant. The first air from which moisture is removed in the firstadsorption heat exchanger (51) flows into the air discharge path (33)through the first air discharge damper (47). After the first air passesthrough the air discharge fan chamber (35), the first air is dischargedto the outside through the air discharge port (21).

On the other hand, the second air flows into the outdoor air path (34)to pass through the outdoor air filter (28), and then flows into thesecond heat exchange chamber (38) through the second outdoor air damper(44). Subsequently, the second air passes through the second adsorptionheat exchanger (52). In the second adsorption heat exchanger (52),moisture desorbs from the adsorbent heated by refrigerant, and then thedesorbed moisture is imparted to the second air. The second airhumidified in the second adsorption heat exchanger (52) flows into theair supply path (31) through the second air supply damper (46). Afterthe second air passes through the air supply fan chamber (36), thesecond air is supplied to the room through the air supply port (22).

<Simple Ventilation Operation>

An action of the outdoor-air conditioner (10) in the simple ventilationoperation will be described with reference to FIG. 8.

During the simple ventilation operation, in the outdoor-air conditioner(10), the first bypass damper (83) and the second bypass damper (84) areopened; and the first room air damper (41), the second room air damper(42), the first outdoor air damper (43), the second outdoor air damper(44), the first air supply damper (45), the second air supply damper(46), the first air discharge damper (47), and the second air dischargedamper (48) are closed. Further, in the simple ventilation operation,the compressor (53) of the refrigerant circuit (50) is stopped.

During the simple ventilation operation, in the outdoor-air conditioner(10), outdoor air is taken into the casing (11) through the outdoor airsuction port (24). The outdoor air flows into the outdoor air path (34)through the outdoor air suction port (24), and then flows from the firstbypass path (81) into the air supply fan chamber (36) through the firstbypass damper (83). Subsequently, the outdoor air is supplied to theroom through the air supply port (22).

Further, during the simple ventilation operation, in the outdoor-airconditioner (10), room air is taken into the casing (11) through theroom air suction port (23). The room air flows into the room air path(32) through the room air suction port (23), and then flows from thesecond bypass path (82) into the air discharge fan chamber (35) throughthe second bypass damper (84). Subsequently, the room air is dischargedto the outside through the air discharge port (21).

Control Operation of Controller

The control operation performed by the ventilation control section (64)of the controller (60) will be described. A room air temperature Trmeasured by the room air temperature sensor (98), an outdoor airtemperature To measured by the outdoor air temperature sensor (99), andan outdoor air dew-point temperature Todew calculated in the outdoor airdew-point temperature calculating section (62) are inputted to theventilation control section (64).

As described above, in the state in which the ventilation operation modeis selected, the simple ventilation operation is performed, therebysupplying outdoor air taken into the casing (11), to the room inunchanged form. However, when performing the simple ventilationoperation under circumstances in which a difference between the outdoortemperature and the room temperature is large, outdoor air having thetemperature which significantly differs from the room temperature issupplied to the room in unchanged form, thereby possibly providingdiscomfort to person(s) in the room.

In addition, when performing the simple ventilation operation undercircumstances in which the humidity of outdoor air is high, there is apossibility of causing condensation of moisture in outdoor air in courseof such air flowing into the room through the inner space of the casing(11). That is, the temperature at a potion of the casing (11), throughwhich room air flows, is approximately equal to the room temperature.The air supply port (22) of the casing (11) is connected to, e.g., ananemo-type (anemostat-type) outlet through a duct. However, such anoutlet is installed in a ceiling surface etc. so as to be exposed to theroom, and the temperature thereof is approximately equal to the roomtemperature. When the portion having the temperature which isapproximately equal to the room temperature is exposed to outdoor airunder circumstances in which the room temperature is lower than theoutdoor air dew-point temperature, condensation of moisture in outdoorair is caused in such a portion. If the condensation of moisture inoutdoor air is caused, there are possibilities that dew condensationwater enters components accommodated in the casing (11), resulting inmalfunctions; or that dew condensation water drops to the room throughthe outlet, resulting in damage of goods in the room.

In order to prevent the above-described problems from being caused whenthe ventilation operation mode is selected, the ventilation controlsection (64) of the controller (60) performs the control operation inwhich, when predetermined conditions are satisfied, the simpleventilation operation is prohibited to limit the operation of theoutdoor-air conditioner (10) to either one of thedehumidification/ventilation operation and thehumidification/ventilation operation. Such a control operation will bedescribed hereinafter with reference to FIG. 10.

Four switching conditions are set in the ventilation control section(64). A first switching condition is a condition where “at least one ofconditions are satisfied, where the room air temperature Tr is lowerthan the outdoor air dew-point temperature Todew (Tr<Todew), and theoutdoor air temperature To is higher than 35° C. (To>35° C.).” A secondswitching condition is a condition where “the operation mode set by auser is either one of the ventilation operation mode and thehumidification operation mode.” A third switching condition is acondition where “the outdoor air temperature To is lower than 5° C.(To<5° C.).” A fourth switching condition is a condition where “theoperation mode set by a user is either one of the ventilation operationmode and the humidification operation mode.”

When not prohibiting the simple ventilation operation, if the first andsecond switching conditions or the third and fourth switching conditionsare satisfied, then the ventilation control section (64) prohibits thesimple ventilation operation to limit the operation of the outdoor-airconditioner (10) to either one of the dehumidification/ventilationoperation and the humidification/ventilation operation. Specifically,when the first and second switching conditions are satisfied, theventilation control section (64) limits the operation of the outdoor-airconditioner (10) to the dehumidification/ventilation operation. On theother hand, when the third and fourth switching conditions aresatisfied, the ventilation control section (64) limits the operation ofthe outdoor-air conditioner (10) to the humidification/ventilationoperation.

When the first switching condition is satisfied during the simpleventilation operation, outdoor air having a temperature higher than 35°C., or outdoor air having a dew-point temperature higher than a roomtemperature is supplied to the room in unchanged form. In addition, whenthe first switching condition is satisfied during thehumidification/ventilation operation, the outdoor air having thetemperature higher than 35° C., or the outdoor air having the dew-pointtemperature higher than the room temperature passes through theadsorption heat exchanger (51, 52) operating as the condenser, to besupplied to the room.

When the first and second switching conditions are satisfied, theventilation control section (64) forcibly switches the operation of theoutdoor-air conditioner (10) from the simple ventilation operation orthe humidification/ventilation operation to thedehumidification/ventilation operation. In thedehumidification/ventilation operation, outdoor air dehumidified andcooled in the adsorption heat exchanger (51, 52) operating as theevaporator is supplied to the room. That is, as compared to the simpleventilation operation and the humidification/ventilation operation, bothof the absolute humidity and temperature of air supplied to the roomfall. This allows a difference between the temperature of air suppliedfrom the outdoor-air conditioner (10) to the room and the roomtemperature to be reduced, thereby alleviating the discomfort ofperson(s) in the room. In addition, since the dew-point temperature ofair supplied from the outdoor-air conditioner (10) to the room is higherthan the room temperature, the condensation of moisture in outdoor airis not caused in course of such air flowing into the room through thecasing (11).

On the other hand, when the third switching condition is satisfiedduring the simple ventilation operation, outdoor air having atemperature lower than 5° C. is supplied to the room in unchanged form.In addition, when the first switching condition is satisfied during thedehumidification/ventilation operation, the outdoor air having thetemperature lower than 5° C. is supplied to the room through theadsorption heat exchanger (51, 52) operating as the evaporator.

When the third switching condition is satisfied, the ventilation controlsection (64) forcibly switches the operation of the outdoor-airconditioner (10) from the simple ventilation operation or thedehumidification/ventilation operation to the humidification/ventilationoperation. In the humidification/ventilation operation, outdoor airhumidified and heated in the adsorption heat exchanger (51, 52)operating as the condenser is supplied to the room. That is, as comparedto the simple ventilation operation and the dehumidification/ventilationoperation, the temperature of air supplied to the room rises. Thisallows a difference between the temperature of air supplied from theoutdoor-air conditioner (10) to the room and the room temperature to bereduced, thereby alleviating the discomfort of person(s) in the room.

An operation reset condition is set in the ventilation control section(64). The operation reset condition is a condition where “all conditionsare satisfied, where the room air temperature Tr is higher than theoutdoor air dew-point temperature Todew by 5° C. or more (Tr≧Todew+5),the outdoor air temperature To is equal to or less than 30° C. (To≦30°C.), and the outdoor air temperature To is equal to or greater than 10°C. (To≧10° C.).”

When limiting the operation of the outdoor-air conditioner (10) toeither one of the dehumidification/ventilation operation and thehumidification/ventilation operation, if the operation reset conditionis satisfied, then the ventilation control section (64) resets theoperation of the outdoor-air conditioner (10) to the operation beforethe operation of the outdoor-air conditioner (10) is limited. That is,if the operation of the outdoor-air conditioner (10) is forciblyswitched from the simple ventilation operation to thedehumidification/ventilation operation or the humidification/ventilationoperation, the ventilation control section (64) returns the operation ofthe outdoor-air conditioner (10) from the dehumidification/ventilationoperation or the humidification/ventilation operation to the simpleventilation operation. In addition, if the operation of the outdoor-airconditioner (10) is forcibly switched from thehumidification/ventilation operation to the dehumidification/ventilationoperation, the ventilation control section (64) returns the operation ofthe outdoor-air conditioner (10) from the dehumidification/ventilationoperation to the humidification/ventilation operation. Further, if theoperation of the outdoor-air conditioner (10) is forcibly switched fromthe dehumidification/ventilation operation to thehumidification/ventilation operation, the ventilation control section(64) returns the operation of the outdoor-air conditioner (10) from thehumidification/ventilation operation to the dehumidification/ventilationoperation.

In the outdoor-air conditioner (10), the dehumidification/ventilationoperation and the humidification/ventilation operation may be prohibitedto enable only the simple ventilation operation to be performed. Whencausing malfunctions in, e.g., the compressor (53) or the four-wayswitching valve (54), the refrigerant cycle cannot be performed in therefrigerant circuit (50), thereby not performing thedehumidification/ventilation operation or the humidification/ventilationoperation. An operation mode in which ventilation of the room iscontinued during nighttime during which there is no person(s) in theroom may be set to the outdoor-air conditioner (10). In such a case, itis useless to perform the dehumidification/ventilation operation or thehumidification/ventilation operation during the nighttime during whichthere is no person(s) in the room, and therefore thedehumidification/ventilation operation and thehumidification/ventilation operation are prohibited to perform only thesimple ventilation operation.

During the simple ventilation operation performed under circumstances inwhich the dehumidification/ventilation operation and thehumidification/ventilation operation are prohibited, it is possible thatthe difference between the room and outdoor temperatures increases, orthat the outdoor air dew-point temperature is higher than the roomtemperature. When continuing the simple ventilation operation with thelarge difference between the room and outdoor temperatures, the roomtemperature becomes closer to the outdoor temperature, therebyincreasing an air-conditioning load when starting air-conditioning ofthe room on the following morning etc. In addition, when continuing thesimple ventilation operation performed under circumstances in which theoutdoor air dew-point temperature is higher than the room temperature,condensation of moisture in outdoor air is caused within the casing (11)or in the outlet etc. exposed to the room. However, in such a case, thedehumidification/ventilation operation or the humidification/ventilationoperation is prohibited, and therefore the above-described problemscannot be prevented by forcibly switching the operation of theoutdoor-air conditioner (10) from the simple ventilation operation tothe dehumidification/ventilation operation or thehumidification/ventilation operation.

When performing the simple ventilation operation under circumstances inwhich the dehumidification/ventilation operation or thehumidification/ventilation operation is prohibited, the ventilationcontrol section (64) performs a control operation for stopping the airsupply fan (26) when a predetermined condition is satisfied, in order toprevent the above-described problems from being caused. Such a controloperation will be described hereinafter with reference to FIG. 11.

A fan stopping condition is set in the ventilation control section (64).The fan stopping condition is a condition where “at least one ofconditions is satisfied and maintained for 20 seconds or more, where theroom air temperature Tr is lower than the outdoor air dew-pointtemperature Todew (Tr<Todew), the outdoor air temperature To is higherthan 35° C. (To>35° C.), and the outdoor air temperature To is lowerthan 5° C. (To<5° C.)”

When the fan stopping condition is satisfied, the ventilation controlsection (64) stops the air supply fan (26). At this point, theventilation control section (64) continues an operation of the airdischarge fan (25), and stops only the air supply fan (26). Whenstopping the air supply fan (26), an outdoor air flow from the outsideto the room through the inner space of the casing (11) is stopped. Thisreduces a change in the room temperature due to the outdoor air supplyto the room, or prevents the condensation of moisture in outdoor air oninner walls of the casing (11) or in the outlet. The ventilation controlsection (64) stops the air supply fan (26) when the fan stoppingcondition is satisfied, and then starts a timer for measuring timeelapsed after the air supply fan (26) is stopped.

In addition, a fan resuming condition is set in the ventilation controlsection (64). The fan resuming condition is a condition where “the timeelapsed after the fan stopping condition is satisfied to stop the airsupply fan (26) is equal to or more than 1 hour.” When the fan resumingcondition is satisfied, the ventilation control section (64) resumes anoperation of the air supply fan (26). In addition, when the fan resumingcondition is satisfied, the time measured by the timer is reset to zeroin the ventilation control section (64).

When the air supply fan (26) is stopped, outdoor air does not flowthrough the casing (11), thereby not measuring outdoor air states(temperature and humidity) by the outdoor air humidity sensor (97) andthe outdoor air temperature sensor (99) installed in the casing (11).Thus, as long as the air supply fan (26) is stopped, it is notdetermined whether or not the operation of the air supply fan (26) canbe resumed.

When 1 hour has elapsed after the fan stopping condition is satisfied tostop the air supply fan (26), the ventilation control section (64)temporarily resumes the operation of the air supply fan (26). When theair supply fan (26) is activated, the outdoor air states (temperatureand humidity) can be measured by using the outdoor air humidity sensor(97) and the outdoor air temperature sensor (99). The ventilationcontrol section (64) continues the operation of the air supply fan (26)if the fan stopping condition is not satisfied under such circumstances;and stops the air supply fan (26) again if the fan stopping condition issatisfied.

ADVANTAGES OF EMBODIMENT

In the outdoor-air conditioner (10) of the present embodiment, when theroom temperature becomes lower than the outdoor air dew-pointtemperature during the simple ventilation operation, the ventilationcontrol section (64) of the controller (60) forcibly switches theoperation of the outdoor-air conditioner (10) from the simpleventilation operation to the dehumidification/ventilation operation.This prevents the simple ventilation operation from being continuedunder circumstances in which the room temperature is lower than theoutdoor air dew-point temperature, thereby shifting to thedehumidification/ventilation operation in which the dehumidified outdoorair is supplied to the room, in such a state. Thus, according to thepresent embodiment, the condensation of moisture in outdoor air duringthe simple ventilation operation can be prevented, and the disadvantagessuch as the malfunctions due to the condensation, and the dropping ofdew condensation water to the room can be prevented in advance.

In the outdoor-air conditioner (10) of the present embodiment, when theoutdoor temperature exceeds the predetermined maximum value (35° C. inthe present embodiment) during the simple ventilation operation, theventilation control section (64) of the controller (60) forciblyswitches the operation of the outdoor-air conditioner (10) from thesimple ventilation operation to the dehumidification/ventilationoperation, thereby decreasing the temperature of air sent into the room.In addition, in the outdoor-air conditioner (10), when the outdoortemperature falls below the predetermined minimum value (5° C. in thepresent embodiment) during the simple ventilation operation, theventilation control section (64) of the controller (60) forciblyswitches the operation of the outdoor-air conditioner (10) from thesimple ventilation operation to the humidification/ventilationoperation, thereby increasing the temperature of air sent into the room.Thus, according to the present embodiment, the difference between thetemperature of air supplied from the outdoor-air conditioner (10) to theroom and the room temperature can be prevented from significantlyincreasing, thereby ensuring comfort in the room.

In the outdoor-air conditioner (10) of the present embodiment, when theroom temperature is lower than the outdoor air dew-point temperatureduring the simple ventilation operation performed under circumstances inwhich the dehumidification/ventilation operation is prohibited, theventilation control section (64) of the controller (60) stops the airsupply fan (26). Thus, according to the present embodiment, even if thedehumidification/ventilation operation cannot be carried out, thecondensation of moisture in outdoor air can be reliably prevented frombeing caused in the portion from the inner space of the casing (11) tothe room.

In the outdoor-air conditioner (10) of the present embodiment, when theoutdoor temperature exceeds the predetermined maximum value (35° C. inthe present embodiment) during the simple ventilation operationperformed under circumstances in which the dehumidification/ventilationoperation is prohibited, the ventilation control section (64) of thecontroller (60) stops the air supply fan (26). In addition, in theoutdoor-air conditioner (10), when the outdoor temperature falls belowthe predetermined minimum value (5° C. in the present embodiment) duringthe simple ventilation operation performed under circumstances in whichthe humidification/ventilation operation is prohibited, the ventilationcontrol section (64) of the controller (60) stops the air supply fan(26). Thus, according to the present embodiment, even if thedehumidification/ventilation operation or the humidification/ventilationoperation cannot be carried out, a decline in the comfort in the roomand an increase in the air-conditioning load can be reduced.

In the outdoor-air conditioner (10) of the present embodiment, therecovery action and the adsorption action are performed in therefrigerant circuit (50).

The dehumidification and cooling of air are performed in parallel in theadsorption heat exchanger (51, 52) during the adsorption action (i.e.,during operating the adsorption heat exchanger as the evaporator), andthe humidification and heating of air are performed in parallel in theadsorption heat exchanger (51, 52) during the recovery action (i.e.,during operating the adsorption heat exchanger as the condenser). Thatis, in the outdoor-air conditioner (10), the air humidity andtemperature controls are performed at a single section. Thus, accordingto the present embodiment, the structure of the outdoor-air conditioner(10) can be simplified as compared to a case where the air humidity andtemperature controls are performed by using separate members.

First Variation of Embodiment

In a refrigerant circuit (50) of the present embodiment, a supercriticalcycle may be performed, in which a high pressure of a refrigerationcycle is set to a value higher than a critical pressure of refrigerant.In such a case, one of a first adsorption heat exchanger (51) and asecond adsorption heat exchanger (52) operates as a gas cooler, and theother operates as an evaporator.

Second Variation of Embodiment

In an outdoor-air conditioner (10) of the present embodiment, adsorbentdeposited on a first adsorption heat exchanger (51) and a secondadsorption heat exchanger (52) is heated or cooled by refrigerant, butthe adsorbent may be heated or cooled by supplying cold or hot water tothe first adsorption heat exchanger (51) and the second adsorption heatexchanger (52).

Third Variation of Embodiment

In the foregoing embodiment, an outdoor-air conditioner (10) may beconfigured as follows.

As illustrated in FIG. 12, the outdoor-air conditioner (10) of thepresent variation includes a refrigerant circuit (100) and twoadsorption elements (111, 112). In the outdoor-air conditioner (10), therefrigerant circuit (100) and the adsorption elements (111, 112) serveas a humidity control means (115).

The refrigerant circuit (100) is a closed circuit in which a compressor(101), a condenser (102), an expansion valve (103), and an evaporator(104) are sequentially connected to each other. When circulatingrefrigerant in the refrigerant circuit (100), a vapor compressionrefrigeration cycle is performed. The first adsorption element (111) andthe second adsorption element (112) are provided with adsorbent such aszeolite. Many air paths are formed in each of the adsorption elements(111, 112), and air is exposed to the adsorbent when passing throughsuch air paths. Each of the adsorption elements (111, 112) serves as anadsorption unit.

The outdoor-air conditioner (10) of the present variation selectivelyperforms a dehumidification/ventilation operation, ahumidification/ventilation operation, and a simple ventilationoperation.

During the dehumidification/ventilation operation or thehumidification/ventilation operation, the outdoor-air conditioner (10)alternately repeats first and second actions at predetermined timeintervals. During the dehumidification/ventilation operation, theoutdoor-air conditioner (10) takes outdoor air as first air, and takesroom air as second air. On the other hand, during thehumidification/ventilation operation, the outdoor-air conditioner (10)takes room air as first air, and takes outdoor air as second air.

First, the first action of the dehumidification/ventilation operationand of the humidification/ventilation operation will be described withreference to FIG. 12(A). During the first action, the outdoor-airconditioner (10) supplies the second air heated in the condenser (102),to the first adsorption element (111). In the first adsorption element(111), the adsorbent is heated by the second air, thereby desorbingmoisture from the adsorbent. In addition, during the first action, theoutdoor-air conditioner (10) supplies the first air to the secondadsorption element (112) to adsorb moisture in the first air onto thesecond adsorption element (112). The first air from which moisture isremoved by the second adsorption element (112) is cooled when passingthrough the evaporator (104).

Next, the second action of the dehumidification/ventilation operationand of the humidification/ventilation operation will be described withreference to FIG. 12(B). During the second action, the outdoor-airconditioner (10) supplies the second air heated in the condenser (102),to the second adsorption element (112). In the second adsorption element(112), the adsorbent is heated by the second air, thereby desorbingmoisture from the adsorbent. In addition, during the first action, theoutdoor-air conditioner (10) supplies the first air to the firstadsorption element (111) to adsorb moisture in the first air to thefirst adsorption element (111). The first air from which moisture isremoved by the first adsorption element (111) is cooled when passingthrough the evaporator (104).

During the dehumidification/ventilation operation, the outdoor-airconditioner (10) supplies the dehumidified first air (outdoor air) tothe room, and discharges the moisture desorbed from the adsorptionelement (111, 112) to the outside together with the second air (roomair). During the humidification/ventilation operation, the outdoor-airconditioner (10) supplies the humidified second air (outdoor air) to theroom, and discharges the first air (room air) from which the moisture isremoved by the adsorption element (111, 112), to the outside.

During the simple ventilation operation, in the outdoor-air conditioner(10), the compressor (101) of the refrigerant circuit (100) is stopped.In addition, outdoor air passes through one of the first adsorptionelement (111) and the second adsorption element (112), and room airpasses through the other. The outdoor air passes through the adsorptionelement (111, 112) to be supplied to the room, and the room air passesthrough the adsorption element (111, 112) to be discharged to theoutside. During the simple ventilation operation, in the outdoor-airconditioner (10), circulation paths of outdoor and room air are notswitched.

Fourth Variation of Embodiment

In the foregoing structure, an outdoor-air conditioner (10) may beconfigured as follows.

As illustrated in FIG. 13, the outdoor-air conditioner (10) of thepresent variation includes a body unit (150) and a heat source unit(165).

An inner space of the body unit (150) is divided into an air supply path(151) and an air discharge path (152). A start point of the air supplypath (151) communicates with an outdoor air suction port (153), and aterminal point thereof communicates with an air supply port (154). Inthe air supply path (151), an application-side heat exchanger (161), ahumidification element (162), and an air supply fan (157) aresequentially arranged from the start point toward the terminal point. Astart point of the air discharge path (152) communicates with a room airsuction port (155), and a terminal point thereof communicates with anair discharge port (156). In the air discharge path (152), an airdischarge fan (158) is arranged.

The heat source unit (165) is connected to the application-side heatexchanger (161) through a pair of connecting pipes (166). Although notillustrated in the figure, the heat source unit (165) includes acompressor, an expansion valve, etc. The heat source unit (165) and theapplication-side heat exchanger (161) form a refrigerant circuit (167).The application-side heat exchanger (161) is an air heat exchanger forexchanging heat between air and refrigerant. The refrigerant circuit(167) selectively performs a refrigeration cycle action in which theapplication-side heat exchanger (161) serves as an evaporator; and arefrigeration cycle action in which the application-side heat exchanger(161) serves as a condenser. In the outdoor-air conditioner (10) of thepresent variation, the refrigerant circuit (167) and the humidificationelement (162) constitute a humidity control means (170).

Although not illustrated in the figure, in the humidification element(162), a water path and an air path are formed with a moisture permeablefilm being interposed therebetween. Tap water supplied from outsideflows in the water path. Air flowing in the air supply path (151)circulates in the air path. The moisture permeable film does not allowwater which is liquid to pass through the moisture permeable film, andallows only water vapor to pass therethrough.

The outdoor-air conditioner (10) of the present variation selectivelyperforms a dehumidification/ventilation operation, ahumidification/ventilation operation, and a simple ventilationoperation.

During the dehumidification/ventilation operation, in the outdoor-airconditioner (10), the refrigerant circuit (167) performs therefrigeration cycle action in which the application-side heat exchanger(161) serves as the evaporator, and a water supply to the humidificationelement (162) is stopped. In such an operation, the evaporationtemperature of refrigerant in the application-side heat exchanger (161)is set to a value lower than the outdoor air dew-point temperature.Outdoor air flowing into the air supply path (151) is cooled whenpassing through the application-side heat exchanger (161), and moisturein the outdoor air is condensed to be drain water. The outdoor airpassing through the application-side heat exchanger (161) passes throughthe humidification element (162), followed by being supplied to a roomthrough the air supply port (154). The drain water generated in theapplication-side heat exchanger (161) is discharged to outside. Room airflowing into the air discharge path (152) is discharged to the outsidethrough the air discharge port (156).

During the humidification/ventilation operation, in the outdoor-airconditioner (10), the refrigerant circuit (167) performs therefrigeration cycle action in which the application-side heat exchanger(161) serves as the condenser, and water is supplied to thehumidification element (162). Outdoor air flowing into the air supplypath (151) is heated when passing through the application-side heatexchanger (161), and then is sent to the humidification element (162).In the humidification element (162), water vapor passing through themoisture permeable film is imparted to air. The air humidified in thehumidification element (162) is supplied to the room through the airsupply port (154). Room air flowing into the air discharge path (152) isdischarged to the outside through the air discharge port (156).

During the simple ventilation operation, in the outdoor-air conditioner(10), both of the operation of the refrigerant circuit (167) and thewater supply to the humidification element (162) are stopped, and onlythe air supply fan (157) and the air discharge fan (158) are operated.Outdoor air flowing into the air supply path (151) sequentially passesthrough the application-side heat exchanger (161) and the humidificationelement (162), and then is supplied to the room through the air supplyport (154). Room air flowing into the air discharge path (152) isdischarged to the outside through the air discharge port (156).

The foregoing embodiments have been set forth merely for purposes ofpreferred examples in nature, and are not intended to limit the scope,applications, and use of the invention.

INDUSTRIAL APPLICABILITY

As described above, the present invention is useful in a humiditycontrol apparatus for controlling humidity in a room.

1. A humidity control apparatus including at least humidity controlmeans (50, 115, 170) for dehumidifying and cooling air, which enables adehumidification/ventilation operation in which the humidity controlmeans (50, 115, 170) dehumidifies and cools outdoor air to be suppliedto a room, and a simple ventilation operation in which the humiditycontrol means (50, 115, 170) is stopped to supply taken outdoor air tothe room in unchanged form, the humidity control apparatus comprising:outdoor temperature detecting means (99) for detecting an outdoortemperature; and control means (64) for forcibly switching from thesimple ventilation operation to the dehumidification/ventilationoperation when the outdoor temperature detected by the outdoortemperature detecting means (99) during the simple ventilation operationexceeds a predetermined maximum value.
 2. The humidity control apparatusof claim 1, wherein the control means (64) stops an outdoor-air supplyto the room when the outdoor temperature detected by the outdoortemperature detecting means (99) exceeds the predetermined maximum valuein the simple ventilation operation performed under circumstances inwhich the dehumidification/ventilation operation is prohibited.
 3. Thehumidity control apparatus of claim 1 or 2, wherein the humidity controlmeans (50, 115) includes adsorption units (51, 52, 111, 112) withadsorbent to be exposed to air, and dehumidifies air by adsorbingmoisture in the air onto the adsorption unit (51, 52, 111, 112).
 4. Ahumidity control apparatus including at least humidity control means(50, 115, 170) for humidifying and heating air, which enables ahumidification/ventilation operation in which the humidity control means(50, 115, 170) humidifies and heats outdoor air to be supplied to aroom, and a simple ventilation operation in which the humidity controlmeans (50, 115, 170) is stopped to supply taken outdoor air to the roomin unchanged form, the humidity control apparatus comprising: outdoortemperature detecting means (99) for detecting an outdoor temperature;and control means (64) for forcibly switching from the simpleventilation operation to the humidification/ventilation operation whenthe outdoor temperature detected by the outdoor temperature detectingmeans (99) during the simple ventilation operation falls below apredetermined minimum value.
 5. The humidity control apparatus of claim4, wherein the control means (64) stops an outdoor-air supply to theroom when the outdoor temperature detected by the outdoor temperaturedetecting means (99) falls below the predetermined minimum value in thesimple ventilation operation performed under circumstances in which thehumidification/ventilation operation is prohibited.
 6. The humiditycontrol apparatus of claim 4 or 5, wherein the humidity control means(50, 115) includes adsorption units (51, 52, 111, 112) with adsorbent tobe exposed to air, and humidifies air by imparting moisture desorbedfrom the adsorbent of the adsorption unit (51, 52, 111, 112), to theair.
 7. The humidity control apparatus of claim 3, wherein the humiditycontrol means includes adsorption heat exchangers (51, 52) withadsorbent deposited on surfaces thereof as the adsorption units, andincludes a refrigerant circuit (50) in which the adsorption heatexchangers (51, 52) are connected to each other to perform arefrigeration cycle; and the refrigerant circuit (50) performs anadsorption action in which the adsorbent of the adsorption heatexchanger (51, 52) is cooled by refrigerant to adsorb moisture in aironto the adsorption heat exchanger (51, 52), and a recovery action inwhich the adsorbent of the adsorption heat exchanger (51, 52) is heatedby refrigerant for recovery of the adsorbent in the adsorption heatexchanger (51, 52).
 8. The humidity control apparatus of claim 6,wherein the humidity control means adsorption heat exchangers (51, 52)with adsorbent deposited on surfaces thereof as the adsorption units,and includes a refrigerant circuit (50) in which the adsorption heatexchangers (51, 52) are connected to each other to perform arefrigeration cycle; and the refrigerant circuit (50) performs anadsorption action in which the adsorbent of the adsorption heatexchanger (51, 52) is cooled by refrigerant to adsorb moisture in aironto the adsorption heat exchanger (51, 52), and a recovery action inwhich the adsorbent of the adsorption heat exchanger (51, 52) is heatedby refrigerant for recovery of the adsorbent in the adsorption heatexchanger (51, 52).